Trademarked as “MemorySil,” the shape-memory material is first being marketed as an earplug called EarJellies, referencing the jelly-like texture of the rubber.

“It is a very soft material that can barely stand up under its own weight, but it remembers shapes and fights to retain them, making it ideal for conforming to the shape of an individual’s ear canal,” said Lou Bloomfield, the UVA physics professor who created the material after a range of experiments over years. “It forms a very good seal for blocking loud sounds.”